Recently, various wireless network technologies have emerged to enable portable endpoint devices (such as laptops, personal digital assistants, cellular telephones, etc.) to communicate both with each other and with wireless networking environments. However, wireless networks are inherently less secure than wired networks, because wired networks may be at least partially located inside a building that can be protected from unauthorized access. Wireless networks do not have the same physical protection and therefore are more vulnerable to attacks. An attacker may use a number of strategies to exploit this vulnerability to pierce network security, corrupt network communications, infiltrate network participants, or compromise routing of network traffic. Accordingly, it is generally desirable to provide an effective security mechanism in wireless networks.